US7357770B1 - Expandable brachytherapy device with constant radiation source spacing - Google Patents

Abstract

A brachytherapy device may include an expandable outer cage, an expandable inner cage positioned within the outer cage and configured to receive radioactive material at its perimeter, and a movable actuator configured to cause the outer and inner cages to expand simultaneously in response to movement of the actuator between certain positions while maintaining a substantially constant separation distance between the outer and inner cages.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is based upon and claims the benefit of U.S. Provisional Patent Application Ser. No. 60/882,391, entitled “EXPANDABLEBRACHYTHERAPYDEVICEWITHCONSTANTRADIATIONSOURCESPACING,” filed Dec. 28, 2006, the entire content of which is incorporated herein by reference.

This application is related to U.S. Provisional Patent Application Ser. No. 60/864,288, entitled “BRACHYTHERAPYDEVICEHAVINGSEEDTUBES WITHINDIVIDUALLY-SETTABLETISSUESPACINGS,” filed Nov. 3, 2006. This application is also related to U.S. patent application Ser. Nos. 11/305,437, entitled “BRACHYTHERAPYAPPARATUS,” filed Dec. 16, 2005, and 11/379,739, entitled “BRACHYTHERAPYAPPARATUS FORASYMMETRICALCAVITIES,” filed Apr. 21, 2006. The entire content of all three of these applications is incorporated herein by reference.

BACKGROUND

1. Field

This application relates to brachytherapy.

2. Description of Related Art

Brachytherapy applies radiation to tissue by placing the source of radiation close to the tissue. Oftentimes, a high dose of radiation is needed. However, it may be difficult to apply a high dose to areas in need of treatment using brachytherapy, without also causing damage to healthy tissue in the vicinity.

One approach to addressing this difficulty is to utilize seed tubes with individually-settable tissue spacings, as described in U.S. Provisional Application Ser. No. 60/864,288, entitled “BRACHYTHERAPYDEVICEHAVINGSEEDTUBES WITHINDIVIDUALLY-SETTABLETISSUESPACINGS,” filed Nov. 3, 2006. The technician may individually set the separation distance between each seed tube that carries a radiation seed and the wall of the cavity in which it is placed.

Expertise may be required to ascertain and set the desired spacings in such a device. The use of different spacings, moreover, may complicate the process of creating and implementing an effective treatment regimen.

SUMMARY

A brachytherapy device may include an expandable outer cage, an expandable inner cage positioned within the outer cage and configured to receive radioactive material at its perimeter, and a movable actuator configured to cause the outer and inner cages to expand simultaneously in response to movement of the actuator between certain positions while maintaining a substantially constant separation distance between the outer and inner cages.

The movable actuator may be configured to cause the outer cage to expand but not the inner cage during movement of the actuator between certain other positions.

The movable actuator may be configured to cause the outer and inner cages to expand in a direction perpendicular to the movement of the actuator.

The brachytherapy device may include a ring that is rotatable about an axis and that is configured to cause the movable actuator to traverse the axis when the ring is rotated. The movable actuator and the rotatable ring may have threads that mesh.

The brachytherapy device may include a handle in which the movable actuator moves. The brachytherapy device may include a rod running through the outer and inner cages that is attached to the handle at a distal end.

The outer and inner cages may each include a plurality of tubes. Each of the tubes and the rod may have a proximal end. The proximal end of all of the tubes and the rod may be affixed to one another. Each of the tubes may have a distal end and the actuator may be configured to engage the distal ends of the tubes. The actuator may be configured to apply longitudinal compressive force to the distal ends of the tubes. The outer and inner cages may be configured to collapse into a rod-like shape when the distal ends of the tubes are not engaged by the actuator.

The inner cage may include hollow tubes, each of which may be configured to receive radioactive material at different locations therein.

A brachytherapy device may include a plurality of flexible outer tubes, each having a first length and a distal end. The device may include a plurality of flexible inner tubes positioned within a volume defined by the outer tubes, each having a second length different from the first length, each being configured to receive radioactive material, and each having a distal end. The device may include a movable actuator configured to engage the distal ends of the outer and the inner tubes.

The distal ends of the outer tubes may lie in a first plane and the distal ends of the inner tubes may lie in a second plane. The first and the second planes may be parallel and separated from one another.

A brachytherapy device may include an expandable outer cage, an expandable inner cage positioned within the outer cage and configured to receive radioactive material at its perimeter, and a rotatable actuation mechanism configured to cause the outer and inner cages to expand in response to rotation of the rotatable actuator between certain positions.

BRIEF DESCRIPTION OF DRAWINGS

The drawings disclose illustrative embodiments. They do not set forth all embodiments. Other embodiments may be used in addition or instead. Details that may be apparent or unnecessary may be omitted to save space or for more effective illustration. When the same numeral appears in different drawings, it is intended to refer to the same or like components or steps.

FIG. 1 illustrates a brachytherapy device in a fully collapsed position.

FIG. 2 illustrates the brachytherapy device illustrated inFIG. 1 after an outer cage has been partially expanded.

FIG. 3 illustrates the expanded outer cage of the brachytherapy device illustrated inFIG. 2 and an inner cage that is still fully collapsed.

FIG. 4 illustrates the brachytherapy device illustrated inFIG. 1 after both the outer cage and the inner cage have been expanded.

FIG. 5 illustrates the expanded outer and inner cages of the brachytherapy device illustrated inFIG. 4.

FIG. 6 is an exploded view of components in the brachytherapy device illustrated inFIGS. 1-5.

FIG. 7 is a cross-section of the tubes illustrated inFIG. 1 in a collapsed state.

FIG. 8 is a cross-section of the handle of the brachytherapy device illustrated inFIG. 1 while in the position shown inFIG. 1.

FIG. 9 is a cross-section of the handle of the brachytherapy device illustrated inFIG. 1 while in the position shown inFIG. 2.

FIG. 10 is a cross-section of the handle of the brachytherapy device illustrated inFIG. 1 while in the position shown inFIG. 4.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Illustrative embodiments are now discussed. Other embodiments may be used in addition or instead. Details that may be apparent or unnecessary may be omitted to save space or for a more effective presentation.

Brachytherapy devices may be used to treat cancerous tissue. Examples of such devices and ways in which they may be used are set forth in U.S. Provisional Patent Application 60/864,288, entitled “BRACHYTHERAPYDEVICEHAVINGSEEDTUBES WITHINDIVIDUALLY-SETTABLETISSUESPACINGS,” filed Nov. 3, 2006, the entire content of which is incorporated herein by reference. Except for differences described in this provisional application, the brachytherapy devices and associated apparatus that are described in the aforementioned provisional patent application, and the ways in which they may be used, may be used in whole or in part in connection with the devices that are described in this application.

FIG. 1 illustrates a brachytherapy device in a fully collapsed position. As shown inFIG. 1, the brachytherapy device may includetubes101 positioned around acentral rod103 and attached to ahandle105 that may include ahandle end cap107 and ahandle front cap109. Arotatable ring111 and anactuator cap113 may be included. Thetubes101 and thecentral rod103 may be attached to one another at a proximal end115 of thetubes101 and thecentral rod103.

The brachytherapy device illustrated inFIG. 1 may be used in many ways. For example, a tumor may be removed from a breast of a patient. The distance between the surface of the breast and the entryway to the cavity may be measured. A sleeve having a length approximately equal to this measurement may be inserted through an incision in the breast until it reaches the entryway to the cavity. The sleeve may include an external flange that may be sutured to the skin of the breast. Details about illustrative apparatuses and processes that may be used are described in United States Provisional patent application entitled “BRACHYTHERAPYDEVICEHAVINGSEEDTUBES WITHINDIVIDUALLY-SETTABLETISSUESPACINGS,” Ser. No. 60/864,288, filed Nov. 3, 2006, the entire content of which is incorporated herein by reference.

The proximal end115 of the collapsed brachytherapy device may be inserted into the sleeve until the proximal end115 passes through the entryway to the cavity and comes into contact with the opposite wall of the cavity.

FIG. 2 illustrates the brachytherapy device illustrated inFIG. 1 after an outer cage has been partially expanded. To expand into this position, therotatable ring111 may have been rotated with respect to thehandle105. This may have caused anactuator202 to traverse the rotational axis of therotatable ring111, as illustrated inFIG. 2. The translation of theactuator202, in turn, may have caused theactuator202 to have compressedouter tubes201 of thetubes101, thus causing them to bow, as illustrated inFIG. 2. Details of mechanisms that may cause this compression are described below in connection withFIGS. 8-10.

As discussed above, thetubes101 of the brachytherapy device may be within a sleeve that has been inserted into the breast. As also explained above, thetubes101 may protrude beyond the sleeve at the entryway to the cavity until their proximal end115 reaches the other wall of the cavity. In this configuration, only the portion of the tubes that lie within the cavity are free to bow. This explains why only the proximal portion of theouter tubes201 are shown as bowed inFIG. 2.

As partially illustrated inFIG. 2,inner tubes203 defining an inner cage may be contained within the volume defined by theouter tubes201 and may remain uncompressed by theactuator202 at this point and thus in an unbowed and collapsed state.

FIG. 3 illustrates the expanded outer cage of the brachytherapy device illustrated inFIG. 2 and the inner cage that is still fully collapsed.

FIG. 4 illustrates the brachytherapy device illustrated inFIG. 1 after both the outer cage and the inner cage have been expanded. To expand into this position, therotatable ring111 may have been rotated further. This may have continued to cause theactuator202 to traverse the rotation axis of therotatable ring111, as illustrated inFIG. 4. As theactuator202 continued to traverse, it may have continued to compress theouter tubes201, thus causing them to bow further. Theactuator202 may also have begun to compress theinner tubes203, thus causing theinner tubes203 to also bow, as also illustrated inFIG. 4. Once therotatable ring111 is rotated to a point that causes theactuator202 to begin to compress theinner tubes203, the inner tubes may bow in substantial unison with theouter tubes201. Again, details of mechanisms that may cause this compression are described below in connection withFIGS. 8-10.

FIG. 5 illustrates the expanded outer and inner cages of the brachytherapy device as shown inFIG. 4.

Therotatable ring111 may continue to be rotated until the cage defined by theouter tubes201 fills the cavity within the breast to a desired degree, such as until the outer cage substantially fills the cavity.

The degree to which the outer cage defined by theouter tubes201 is expanded may vary to match different size breast cavities. However, the spacing between theinner tubes203 and theouter tubes201 and thus the surface of the cavity may remain substantially constant, notwithstanding these difference in expansion. The phrase “substantially constant” is intended to take into consideration small changes in the separation distance that may occur due to the geometries of the arrangement.

As should now be apparent, both the outer cage and the inner cage may be expanded to needed positions merely by the rotation of a single component, namely in this embodiment, therotatable ring111.

FIG. 6 is an exploded view of components of the brachytherapy device illustrated inFIGS. 1-5. As shown inFIG. 6, theactuator202 may includethreads601 configured to mate withcorresponding threads604 in therotatable ring111. Theactuator202 may includetabs603 and605 that may engage corresponding slots in thehandle105. For example, thetab605 may engage aslot607 in thehandle105. A retainingring609 may also be attached to thehandle105 so as to insure that theactuator202 is retained within thehandle105.

The net effect of the components that have thus-far been described in connection withFIG. 6 may be to cause theactuator202 to traverse the rotational axis of therotatable ring111 as therotatable ring111 is rotated. Rotation of therotatable ring111 may pull on thethreads601 on theactuator202, while thetabs603 and605 and their corresponding slots in thehandle105 may prevent the actuator202 from also rotating, thus causing theactuator202 to traverse the rotation axis of therotatable ring111.

As also shown inFIG. 6, theouter tubes201 may have a length that is shorter than theinner tubes203. Similarly, theinner tubes203 may have a length that is shorter than thecentral rod103.

FIG. 7 is a cross-section of the tubes illustrated inFIG. 1 in a collapsed state. As shown inFIG. 7, theouter tubes201 may define an interior volume in which theinner tubes203 reside. Similarly, theinner tubes203 may define an interior volume in which thecentral rod103 resides. As also illustrated inFIG. 7, each of theinner tubes203 and each of theouter tubes201 may be hollow. In an alternate embodiment, one or more of the inner and/or theouter tubes201 may not be hollow.

FIG. 8 is a cross-section of the handle of the brachytherapy device illustrated inFIG. 1 while in the position shown inFIG. 1. As shown inFIG. 8, ascrew801 may secure adistal end803 of thecentral rod103 to thehandle end cap107.

While in the position shown inFIG. 8, theactuator202 may not apply any pressure todistal ends811 of theouter tubes201 or todistal ends807 of theinner tubes203, thus allowing theouter tubes201 and theinner tubes203 to be in the completely collapsed position illustrated inFIG. 1.

FIG. 9 is a cross-section of the handle of the brachytherapy device illustrated inFIG. 1 while in the position shown inFIG. 2. In order to have gotten into the position illustrated inFIG. 9, therotatable ring111 may have been rotated, thus causing theactuator202 to have traversed the rotational axis of therotatable ring111, as illustrated inFIG. 9. As it began this traverse, anannular surface901 within the interior of theactuator202 may have engaged the distal ends811 of theouter tubes201, thus applying longitudinal compressive force on theouter tubes201 with respect to thecentral rod103 whosedistal end803 may be attached to thehandle end cap107 by thescrew801. This longitudinal compression may have caused the length of theouter tubes201 that protrudes beyond the sleeve (see discussion above) to bow, as illustrated inFIGS. 2 and 3.

As illustrated inFIG. 8, theactuator202 may have a secondannular surface805 on its interior which may initially be longitudinally separated from the distal ends807 of theinner tubes203. Thus, longitudinal pressure may not be asserted by the secondannular surface805 against the distal ends807 of theinner tubes203 during the initial portion of the traverse of theactuator202.

Once therotatable ring111 is rotated by a certain amount, thegap809 between the secondannular surface805 and the distal ends807 of theinner tubes203 may close, thus causing the secondannular surface805 to engage the distal ends807 of theinner tubes203, as illustrated inFIG. 9.

FIG. 10 is a cross-section of the handle of the brachytherapy device illustrated inFIG. 1 while in the position shown inFIG. 4. As therotatable ring111 continues to be rotated past the point shown inFIG. 9, theactuator202 may apply longitudinal compressive force simultaneously to both theouter tubes201 and theinner tubes203 by virtue of force being applied by theannular surface901 to the distal ends of theouter tubes201 and by the secondannular surface805 to the distal ends807 of theinner tubes203. This may cause theouter tubes201 and theinner tubes203 to bow in unison. In turn, this may cause the distance between theouter tubes201 and theinner tubes203 to remain substantially constant, notwithstanding continued bowing of theouter tubes201 and theinner tubes203.

Therotatable ring111 may continue to be rotated until the cage defined by theouter tubes201 expands to the desired amount or until theactuator202 is prevented from traversing any further through the rotational axis of therotatable ring111 by thefront cap109.

After theouter tubes201 have been expanded to the desired or maximum amount, the shaft of thetubes101 at the entryway to thehandle105 may be clamped, thehandle105 may be detached from thetubes101 by cutting thetubes101 between the clamp and thehandle105, and one or more radiation sources, such as one or more radioactive seeds, may be inserted into the hollow interior of one or more of theinner tubes203 and/or theouter tubes201 in accordance with a treatment plan. Examples of apparatuses and related processes that may be used in connection with these steps are described in U.S. Provisional Application Ser. No. 60/864,288, entitled “BRACHYTHERAPYDEVICEHAVINGSEEDTUBES WITHINDIVIDUALLY-SETTABLETISSUESPACINGS,” filed Nov. 3, 2006, the entire content of which is incorporated herein by reference.

The components, steps, features, objects, benefits and advantages that have been discussed are merely illustrative. None of them, nor the discussions relating to them, are intended to limit the scope of protection in any way. Numerous other embodiments are also contemplated, including embodiments that have fewer, additional, and/or different components, steps, features, objects, benefits and advantages. The components and steps may also be arranged and ordered differently.

For example, a fluid barrier, such as an expandable sheath, may be placed around thetubes101 so as to prevent fluid from filling the cage defined by theouter tubes201 both before and after they are expanded. The interior of this fluid barrier may be filled with air or fluid from an external source. For example, thecentral rod103 may have a lumen through which fluid may be delivered from outside of the breast. The fluid may flow into the interior of the fluid barrier through one or more holes in the proximal end of the central rod103 (not shown).

Although theannular surfaces805 and901 have thus-far been illustrated as being in separate planes, these two surfaces could instead be replaced by a single annual surface. In this embodiment, the differential in the lengths of theouter tubes201 and theinner tubes203 may be increased to compensate. Conversely, the lengths of theouter tubes201 and theinner tubes203 may be the same, while theannular surfaces805 and901 may be separated by a greater distance to compensate.

The amount of the substantially constant spacing between theouter tubes201 and theinner tubes203 may be varied by a variety of means. For example, different tube sets may be provided, each with a different distance between the distal ends of theouter tubes201 and theinner tubes203. The technician may select the tube set that will provide the desired separation distance. Similarly, different handles may be provided which have different longitudinal spacings between the twoannular surfaces805 and901. In this event, the technician may instead select the handle that will provide the desired spacing. In a still further embodiment, the longitudinal location of theannular surface805 and/or theannular surface901 may be adjustable.

Although certain mechanical designs have been described to effectuate the bowing of thetubes101, these are only examples. Any other design may be used instead.

Appropriate apparatuses may also be provided to allow the degree of bowing in theinner tubes203 and/or theouter tubes201 to be individually adjusted either before, during or after these tubes are bowed in unison as a result of the rotation of therotatable ring111. U.S. Provisional Patent Application Ser. No. 60/864,288, entitled “BRACHYTHERAPYDEVICEHAVINGSEEDTUBES WITHINDIVIDUALLY-SETTABLETISSUESPACINGS,” filed Nov. 3, 2006, sets forth examples of apparatuses that may be used to effectuate such individual adjustments. Any of the apparatuses and methods shown in U.S. patent application Ser. Nos. 11/305,437, entitled “BRACHYTHERAPYAPPARATUS,” filed Dec. 16, 2005, and 11/379,739, entitled “BRACHYTHERAPYAPPARATUS FORASYMMETRICALCAVITIES,” filed Apr. 21, 2006, may be used in addition or instead.

Although having thus-far been describe for use in connection with treating a breast, the brachytherapy devices and methods that have been described may also be used to treat other areas of a body, such as the brain or prostrate.

The phrase “means for” when used in a claim embraces the corresponding structures and materials that have been described and their equivalents. Similarly, the phrase “step for” when used in a claim embraces the corresponding acts that have been described and their equivalents. The absence of these phrases means that the claim is not limited to any of the corresponding structures, materials, or acts or to their equivalents.

Nothing that has been stated or illustrated is intended to cause a dedication of any component, step, feature, object, benefit, advantage, or equivalent to the public, regardless of whether it is recited in the claims.

In short, the scope of protection is limited solely by the claims that now follow. That scope is intended to be as broad as is reasonably consistent with the language that is used in the claims and to encompass all structural and functional equivalents.

Claims (15)

1. A brachytherapy device comprising:

an expandable outer cage;

an expandable inner cage positioned within the outer cage and configured to receive radioactive material at its perimeter;

a movable actuator configured to cause the outer and inner cages to expand simultaneously in response to movement of the actuator between certain positions while maintaining a substantially constant and non-zero separation distance between the outer and inner cages;

a handle in which the movable actuator moves; and

a rod running through the outer and inner cages that is attached to the handle at a distal end.

2. The brachytherapy device ofclaim 1 wherein the movable actuator is configured to cause the outer cage to expand but not the inner cage during movement of the actuator between certain other positions.

3. The brachytherapy device ofclaim 1 wherein the movable actuator is configured to cause the outer and inner cages to expand in a direction perpendicular to the movement of the actuator.

4. The brachytherapy device ofclaim 1 further comprising a ring that is rotatable about an axis and that is configured to cause the movable actuator to traverse the axis when the ring is rotated.

5. The brachytherapy device ofclaim 4 wherein the movable actuator and the rotatable ring have threads that mesh.

6. The brachytherapy device ofclaim 1 wherein the outer and inner cages each include a plurality of tubes, wherein each of the tubes and the rod have a proximal end, and wherein the proximal end of all of the tubes and the rod are affixed to one another.

7. The brachytherapy device ofclaim 6 wherein each of the tubes has a distal end and wherein the actuator is configured to engage the distal ends of the tubes.

8. The brachytherapy device ofclaim 7 wherein the outer and inner cages are configured to collapse into a rod-like shape when the distal ends of the tubes are not engaged by the actuator.

9. The brachytherapy device ofclaim 6 wherein the actuator is configured to apply longitudinal compressive force to the distal ends of the tubes.

10. The brachytherapy device ofclaim 1 wherein the inner cage is comprised of hollow tubes, each of which are configured to receive radioactive material at different locations therein.

11. A brachytherapy device comprising:

an expandable outer cage;

an expandable inner cage positioned within the outer cage and configured to receive radioactive material at its perimeter; and

a rotatable actuation mechanism configured to cause the outer and inner cages to expand and to be spaced apart in response to rotations of the rotatable actuator between certain positions.

12. The brachytherapy device ofclaim 11 wherein the expandable inner cage is comprised of hollow tubes, each configured to receive radioactive material at different locations therein.

13. The brachytherapy device ofclaim 11 wherein the outer and inner cages are configured to collapse into a rod-like shape when not expanded by rotation of the rotatable actuation mechanism.

14. The brachytherapy device ofclaim 11 wherein rotation of the rotatable actuation mechanism between certain other positions causes the outer cage to expand but not the inner cage.

15. The brachytherapy device ofclaim 11 wherein the rotatable actuation mechanism includes a ring and an actuator.

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